Sealing-in machine for tubes and bulbs



Jan. 3, 1928.

c. EISLER SEALING-IN MACHINE FOR TUBES AND BULBS Filed April 25, 1925 2Sheets-Sheet 1 ATTORNE Jan. 3, 1928.

C. EISLER SEALING-IN MACHINE FOR TUBES AND BULBS Filed April 25, 1925 2Sheets-Sheet 2 I lllll IIIH 17 M05. L y 74v ATTORNEY Patented Jan. 3,1928.

UNITED STATES PATENT OFFICE.

s nmin fled April :5, 1m. Serial Io, 25,747.

This invention.'relates-to a machine for.

sealing in the stems of radio tubes and the like and particularly tosealing in of the character set forth in my apphcatlon Serial No. 6,527,filed February 3, 1925. That application coversa novel method of formingstems of the general character set forth in J aeger Patent No. 729,182,May 26,

1903 and comprising generally a stem'tube with a flare for sealmg to thebulb or tube neck, and an exhaust tube havin its inner end bentlaterally ,and fused to t e side of the stem tube at a point removedfrom the sealed end thereof. The machine of the present a plication isof more general application, owever as to certain of its features,

' and may be utilized, for example, for sealing tated and the sealing-inexpedited. A still further object is a mechanism of the above indicatedcharacter including a novel single oint sup ort for the stem while beingsealed mto the ulb or tube whereby strams and breakages aresubstantially reduced during the sealing-in and the removal of thesealedin bulb may be readily and quickly efiected for centering themount, if necessary, b the operator before the setting of the p asticseal. A still further object is the automatic removal of the stemsupport, if desired, after the fusing takes place and before the settingwithout exerting pull on the plastic seal. My invention alsocontemplates a simplified revolving head structure whereby the parts maybe economically produced and assembled and adjustments thereoffacilitated for various sizes of lamps, and a simplified driving andcontrol mechanism for effecting the intermittent and rotating movements.

For a better understanding of the above indicated novel features of theinvention and others which will hereinafter appear, reference may be.had to the accompanying 'drawmgs forming a part of this specification,wherem:

Fig. 1 is a plan view of a sealing-in machme embodymg m invention, moreor less dlagrammatlcallyi ustrated,

Fig. 2 is a sectional view of the machine along the lines 22 of Fig. 1,

F1g. 3 1s a s de view, partly in section, of a il'ivolving head orspindle and associated P l Fig. 4 is a sectional view of the upper partof dthe stem support and cooperating parts, an

- Fig. 5 is a sectional view of the lower part thereof.

Referring to the drawings where like numerals designate similar partsthroughout, I have mdicate'dmy invention as embodied in a machine havinga trough like stationary base or table 17, the latter being carried bysultable standards, a' rotatable spider or frame 10 which is mounted forintermittent rotation thereon and a plurality of rotatable heads 1carried by the spider 10. In the particular embodiment hereinillustrated there are six of these heads 1, although in practice as manof these heads may be provided as are esired. Intermittent movement ofthe spider 10 is efiected through the med um of Geneva wheel 16 on theshaft 13 which is keyed to the spider, the Geneva wheel being driven bya cooperating driver 14' on a vertical counter-shaft 12, mounted insuitable bearings carried by the table 17. A worm gear 11 1s mounted onthe Geneva 'driver shaft 12 and driven by the worm 15 on the drivingshaft 2.

The various heads succemively occupy the pos tions A, B, O, D, E, and Fas the ider 10 1s intermittently rotated, A and B in the two frontpositions where the sealed tubes or bulbs are taken off and new tubesand stems are inserted, while at positions C, D, E the parts to be fusedtogether are gradually heated and at the position'F the concentratedheat applied to complete the fusing and the sealing of the bulb and stemtogether. The heads 1 with the bulbs and stems carried thereby arerotated about their axes at the positions C, D,'E and F from the drivingshaft 2 bymeans of are 3 keyed to "the respective splndles and t erubber frictional drive wheels 4 which are carried by vertical countershafts 7 rotatably mounted in the table 17 there being a rubber drive 4passes an endless chain 5.

adjacent each of the heating positions G, D, E, F. The shafts 7 pro ectdownwardly through the table 17 an carry on the under side a series ofsprockets 6 around which shafts 7 also carries on its lower end a spiralgear 9 which. meshes with a cooperating spiral gear 8 on the drive shaft2 for continuously rotatin the drivers 4. The tubes and stems, assem ledon the heads 1 1n either position A or B, are intermittently carried.

and the latter in turn carry on their upperends the bulb or tube support30. The support is capable of adjustment longitudinally of the supports29 and may be fixed in any desired position by means of the set screws31. Each base 27 includes a hollow shaft 27 which is journaled asindicated on the spider 10 and carries on its lower end the driving gear3. Through the center of the base 27 and the hollow shaft 27' passes thestem support including a hollow sealing rod 19, and this rod carriesw1th1n its upper end the stem adapter and support 32, 35. The stemadapter is of tubular formand closed at its lower end, and it consistsof two parts, a lower part which is screwthreadedly attached at itsupper end to the interior of the upper end of the seallng rod 19 and anupper part 32 which is separably mounted within the upper part 35, theupper part being thereby removable without removing the whole support.Thetubular member 32-35 may be adjusted longitudinally of the sealingrod by means of the adjustable nut 36 which is screw-threadedly attachedto the upper end of the part 35 and en es the upper end of the sealingrod 19. set screw 37 is provided for anchoring this nut in any adjustedposltlon. The part 35 of the stem adapter for the greater portion of itslength below the externally threadedportion at the top is made ofsmaller diameter than the interior diameter of this sealing rod 19, butat its extreme lower end it has an exact fit with the bore of thesealing rod. Longitudinal grooves 20' are provided along the surface ofthe lower end of the part 35 and similar grooves 20 are cut through theexternal threadedportions of the upper end thereof for a purposehereinafter set forth. In the particular embodiment herein, there areshown three such grooves equally spaced around both the upper and lowerends of the part 35 of the stem support. The stem adapter ma be providedat its upper end with a circu ar flange 41 One of these.

for engaginglthe flare of-the stem tube and sup rting t e stem in thedesired position,

an the stem support is provided with a flaring opening at 1ts u per endto facilitate the insertion of the ste s with theirexhaust.

-tubes projecting downwardly and loosely therein and to permit readyremoval-of the lamp bulbs or tubes after the sealing-in operation.

The sealing rod 19 is provided on its lower end with a circular shoe 34and between the latter and the end of the hollow shaft 27 there isdisposed a spring 23 which normally urges the sealing rod and the shoe3.4 in a downward direction against the circular track 24 carried by thetable 17 The track 24 preferably has a'bevelled 01f portion indicated at24' in Fig. 3. This is for the purpose of causing an automatic loweringof the sealing rod 19 with the stem adapter 32 35 at posltions A and Bto facilitate the ta ing off of the finished bulbs and lacing of newparts thereon. An adjustable sto 25 is carried by the base portion 27whic coe erates with a collar 33 carried by the sea ing red at a pointthereabove to limit the downward movement of the sealing rod. A key 26in the base 27 cooperates -with a long keyway 28 in the sealing rod 19to effect the rotation of the rod 19 with the base 27, but at the sametime permitting the .longitudinal relative movement, if desired.

The beveled off portion 24' may beginimmediately after leaving theposition F and in that case, the Weight of the filament stem may besuflicient to lower or tilt the filament stem and mount with referenceto the bulb, due to the fused and plastic condition of the seal.However, the operator upon removal of the bulb may, if necessary,slightly adjust the stem with reference to the bulb to properly ositionthe mount therewithin, since usual y the seal is still slightly plasticwhen position A is reached. The operation of the iealing inmachine issubstantially as folows:

the operator inserts within the stem adapter Upon the heads located ateither A or It 32, 35 a stem with its exhaust tube 43 extending looselydown into the stem tube su port and with its flare 44 resting upon theange support 41. She also inserts over this stem and within the tubesupport 30 a tube 45 with its neck or skirt 46 extending down beyond theflare 44. With the parts thus assembled at position B, at the nextintermittent operation the head 1 is automatically moved to position Gwhere the driver u 11 coming into driving relation with the rub r wheel4 at that position is rotated while a flame from the single burner 40 iscaused to play upon the bulb or tube neck'in the vicinity of the flare44. At the next intertion D where two or more flames are-caused numberof flames neck and at positio concentrated flames are brought to bearupon the neck in the.

vicinity of the flare 44 which causes the fusing or welding of the flare44 of the stem to the neck with considerable attenuation of the neck orskirt 46 down beyond the flare. At this position F a small continuouslyflowing blast of air from the nozzle 47 is directed up into the lowerend of the hoHow sealing rod 19 which blast of air passes upwardly inthe direction of the arrows in Figs. 4 and 5 through thegrooves and 20and to the space above the ML justing nut 36, theair pressure beingsufii: cient to blow off the surplus glass as it is melted from thelower portion of the neck Est below the flare 44. The tube may providedwithra lateral opening 48 regis-' termg with a smaller opening 49 in thesealing rod 19 to keep the interior of the tube or bulb in communicationwith the atmosphere, as such communication is always essential insealing stems into bulbs. The head stays at osition F long enough toeffect the seal w ereupon the intermittent o eration takes place againand the head t en goes to position A where the finished tube is removedto provide for the positioning of another bulb and stem to be sealed in.After leavin position F the stem support is automatica ly lowered by theshoe 34 running down the cam surface 24'.

This automatically removes all support for and engagement with the stem,permitting the latter to yield freely during the cooling of the weldwithout hindrance from the support. Moreover, the lowering of the stemsupport at positions A and B facilitates I'claim and desire to thepositioning of the lamp parts thereon.

The sur his neck 46 of the tube 45, if not broken be ore it reachespositions A and B is'broken ofi by the operator whereupon it falls intothe trough like table 17 and from there it is carried by a brush or rake22 to an opening 21 in the table for dumping into asuitable receptacle.Y

Having thus described my invention, what protect by. Letters Patent is:g y

1. In a head for machines for sealing mounts in tubes or bulbs. a hollowrod having an opening through its wall, and a stem adapter secured nearits upper end therein with a portion of the adapter extending above therod and terminating in a seat for engaging the flare of the mount to besealed in, the stem adapter being hollow to .loosely receive the exhausttube of the mount, the lower end of. the adapter being of a diameter tofit the bore of the rod and protenor well open at the top and mounts intubes adapter which is externally l I vided with an externallongitudinal slot constitutin a passage for air to blow of! the fusedgIass and a so provided with an open ing through its wall adapted toregister with thia1 opening through the wall of said hollow ro 2. In ahead for machines for sealing mounts in tubes or bulbs, a stem ada terprovided with a seat at one end adapts to engage the .flare of the mountwith an inclosed at its bottom to receive the exhaust tube of the mountand with thickened walls at its lower end formed with one or moreexternal longitudinal slots, and with an opening throu h the unslottedportion of the'thickened wa and a-hollow tube surrounding the adapter,fitting tightly the thickened walls thereof and provided with a wallopening registering with that in tl1e wall of the ada ter.

3. In a head for machines or sealing or bulbs, a stem ada ter providedwith a engage theflare, of the mount, with an interior well open at thetop and closed at its bottom to receive the exhaust tube of the mountand with thickened walls at its lower end formed with one or morelongitudinal slots, and with an openin through the unslotted portion ofthe thic ened wall, and a hollow tube surroundin the adapter, fittingtightly the thickened walls thereof and provided with a wall openingregistering with that in the wall of the adapter, the adapter and tubehaving exterior and interior screw-threads securing them together.

4. In a head for machines for sealing mounts in tubes or bulbs, a stemadapter formed with a seat for the mount and a well to receive theexhaust tube of the mount, the

adapter being closed at the bottom, an outer tube secured about theadapter, said tube and adapter being formed to provide passages forpassage of air around the tube to points below the seat of the adapterand with a separate air pamage from within the well through the walls ofthe adapter and tube.

5. In a sealing in machine a revolving head including a bulb support anda stem support adapted to support a stem in sealing relation with thebulb, said stem support including a hollow sealing rod, a stem threadednear its upper end to engage with the internally threaded upper end ofthe sealing rod and an adjustable nut disposed about the threadedportion of the adapter for adjusting the adapter to difierent positionswithin the seal ngrod.

6. In a sealin in machine for lamp bulbs or tubes, a revo ving headincluding a bulb support, a stem support, said stem support be1ngadapted to engage the stem only by the restin of the stem upon the upperend of the stem support, means for intermittently seat at one end adapteto moving said revolving head from one po'sition to another and meansfor automatically removing the stem support from engagement with thestem without exerting "any pull thereu on immediately after the seal 15efiected an before the plastic weld becomes set. I

7. In asealing-in machine forlamp bulbs or tubes a trough like table, arevpluble frame thereon carrying a multiplicity of revoluhle heads forsealing ,in lam bulbs and fusing' ofi the surplus necks of tlfehulbs dthe scaling in operation, and a brush carri by the revoluble frame andengaging the interior-of the trough like table to con- 1l ve the surplusglass to an opemng provi ed in the table.

In testimony whereof, I haveiaigned my name to this specification.

CHARLES EISLER.

